ASME Ⅷ-2中的目视检测

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ASME Ⅷ-2中的目视检测

VT-目视检测

一、ASME Section V article 9 edition中对人员的要求

1）T-923 PHYSICAL REQUIREMENTS体检要求

Personnel shall have an annual vision test to assure natural or corrected near distance acuity such that they are capable of reading standard J-1 letters on standard Jaeger test type charts for near vision. Equivalent near vision tests are acceptable.

人员应每年做一次视力检查，以保证正常的或正确的近距离分辨能力。他们能读出近距离视力典型标准Jaeger 测试图表的标准J-1字母，对于等效近距离视力测试是可以接受的。

2）T-952 DIRECT VISUAL EXAMINATION直接目视检测

Direct visual examination may usually be made when access is sufficient to place the eye within 24 in. (600 mm) of the surface to be examined and at an angle not less than 30 deg to the surface to be examined. Mirrors may be used to improve the angle of vision, and aids such as a magnifying lens may be used to assist examinations. Illumination (natural or supplemental white light) of the examination surface is required for the specific part, component, vessel, or section thereof being examined. The minimum light intensity shall be 100 fc (1076 lx). The light intensity, natural or supplemental white light source, shall be measured with a white light meter prior to the examination or a verified light source shall be used. Verification of light sources is required to be demonstrated only one time, documented, and maintained on file.

当能充分靠近，而使眼睛离被检表面不超过24in.(610mm，注：单位换算问题)，与被检表面所成的视角不小于30°时，则一般可采用直接的目视检验。可以采用反光镜来改善观察的角度，并可借助于放大镜之类来帮助检验。在直接检验时，对具体的零件、部件、容器或容器的某个需要检验的部位需要一定的光照度(自然光，或辅助白炽光)。最小的光照度应为100fc(1000lx)。在检验前，光强度、自然光、或辅助白炽光或验证光源时，应用白光仪表进行测量。光源验证演示仅要求进行一次，并制成文件记录存档。